<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="box">
      <button v-on:click="count--">-</button>
      <span>{{ count }}</span>
      <button v-on:click="count++">+</button>
    </div>
    <script src="./vue.js"></script>
    <script>
      new Vue({
        el: "#box",
        data: {
          count: 0,
        },
      });
    </script>
  </body>
</html>
